This study is important because it deals with 21st century skills and current techniques in the field of educational technology and the studies in this field are limited in the literature. The purpose of this study is to determine the effects of coding, robotics, 3D design and game design education on problem solving and reflective thinking skills of 8/10-year-old students and on problem solving and metacognitive awareness levels of 11/14-year-old students. In this study, a quasi-experimental research model with a single group pre-test / post-test pattern, which is considered one of the quantitative research methods, was used. The research was carried out with a total of 36 participants, 15 in the 8-10 age group and 21 in the 11-14 age group, enrolled in a course organized by a higher education institution. The duration of the training is 8 weeks, 2 hours per week. The data of this study were collected through a questionnaire. The questionnaires used consist of 2 parts: Problem Solving Inventory and Reflective Thinking Skills Scale for Problem Solving for Primary Education Level Children aged 8-10, and Problem Solving Inventory and Metacognitive Awareness Inventory for Children - Form B for 11/14-year-old students. As a result of all these applications, it was observed that there was an increase in students' problem solving and metacognitive awareness skills, but it was not statistically significant. It was observed that there was a statistically significant increase in the reflective thinking skills of 8/10-year-old students.